Simulating vertical water mixing in homogeneous estuaries: [2pt] the SADO Estuary case

In this article, a three-dimensional primitive equation model is applied to Sado Estuary, which is a meso-tidal homogeneous estuary. Despite the homogeneity of its density field, the flow presents important vertical structures. This article shows that the common practice of using two-dimensional depth-integrated models in homogeneous estuaries can filter important vertical hydrodynamic features, such as secondary and circulating flows. The physical processes associated with these flows are analysed. The strong curvature of the channels and the strong bathymetry gradients were identified as the principal morphologic features of the estuary responsible for the generation of the flows. The model possesses a generic vertical mesh geometry approach, which is used to test the sensibility of the model to the vertical discretization when simulating these flows.